Top fire would mostly be usable in tank type games like battlezone. On the picture provided that's a bad setup, as it should have 2 joys, of which one would have top fire, otherwise there is little purpose for a single joy to have top fire, I guess you could use it with tron maybe?
One more game that would be usable SDI-strategic defense initiative you would need joy with top fire for optimal playability as your other hand is occupied with trackball (please no innuendos here!)
